1. Field of the Invention
The present invention relates to a microphone apparatus.
2. Description of the Related Art
In a videoconference, for example, generally, speech of speakers is picked up by a microphone on a table. The microphone may also pick up ambient noise, and an unclear speech signal may be output from the microphone. There are methods for picking up speech of speakers by using a microphone in order to obtain a clear speech signal.
A first method is to use a directional microphone and to give emphasis on speech while suppressing noise when the speech is input to the microphone. A second method is to adaptively process a speech signal output from a microphone to reduce noise components. The first and second methods relatively reduce the level of the noise components included in the speech signal, thereby obtaining a clear speech signal.
A microphone apparatus employing the first method includes six microphones disposed around a reference microphone (microphone unit), in which the outputs of the microphones are combined using a Fourier transform so that the overall microphone apparatus provides unidirectional performance.
This microphone apparatus is disclosed in Japanese Unexamined Patent Application Publication No. 2002-271885.